Optical character recognition (OCR) refers to a process of electronically extracting text from images. The images may correspond to scanned versions of printed matter, such as book pages, magazine pages, newspaper articles, invoices, account statements, business cards, or other printed text. The quality of OCR has improved over the years. While early versions of OCR required the use of special fonts, current versions of OCR can recognize text in most fonts with a high degree of accuracy. However, problems with OCR persist for certain types of documents.